jsp简单的mvc架构新闻发布系统

package com.lisi.news.logic; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List; import com.lisi.news.comm.DataSource; import com.lisi.news.data.NewsDataBean; //业务逻辑类 //这个类的任务是分页，并把分页后每页的所有记录放到列表中返回 //本类采用假分页算法 public class NewsLogicBean { /** * @param args */ private int allRows;//总行数 private int curPage=1;//当前页 private int rowPerPage=5;//每页多少行 private int allPages; //总页数 public int getAllRows() { return allRows; } public void setAllRows(int allRows) { this.allRows = allRows; } public int getCurPage() { return curPage; } public void setCurPage(int curPage) { this.curPage = curPage; } public int getRowPerPage() { return rowPerPage; } public void setRowPerPage(int rowPerPage) { this.rowPerPage = rowPerPage; } public int getAllPages() { return allPages; } public void setAllPages(int allPages) { this.allPages = allPages; } public List findAll() { // List列表、Set集合 为单值 // Map键值对 为双值 List list= new ArrayList(); Statement st=null; ResultSet rs=null; try { st=DataSource.getConnection().createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY); //该行进行 try catch 并在其下加入 结果集可进行滚动 游标只读 rs=st.executeQuery(" select newsid,newstitle,newscontent,newscount,newsdate from news order by newsdate desc"); rs.last(); //定位到最后一行 this.allRows=rs.getRow();//总共多少行 if(this.allRows%this.rowPerPage==0){ this.allPages=this.allRows/this.rowPerPage; }else{ this.allPages=this.allRows/this.rowPerPage+1; } if(this.curPage==1){ rs.beforeFirst(); }else{ rs.absolute((this.curPage-1)*this.rowPerPage); } int i=0; while(rs.next()&&i<this.rowPerPage){ NewsDataBean bean=new NewsDataBean(); bean.setNewsid(rs.getString(1)); bean.setNewstitle(rs.getString(2)); bean.setNewscontent(rs.getString(3)); bean.setNewscount(rs.getString(4)); bean.setNewsdate(rs.getString(5)); list.add(bean); i++; } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return list;//list.size()可能为5，也可能为0 } public int insertNews(String newsTitle,String newsContent){ return modify("insert into news(newstitle,newscontent,newscount,newsdate) values('"+newsTitle+"','"+newsContent+"',0,now())"); } public NewsDataBean findById(String newsid){ NewsDataBean bean=new NewsDataBean(); Statement st=null; ResultSet rs=null; try { st=DataSource.getConnection().createStatement(); rs=st.executeQuery("select newsid,newstitle,newscontent,newscount,newsdate from news where newsid="+newsid); if(rs.next()){ bean.setNewsid(rs.getString(1)); bean.setNewstitle(rs.getString(2)); bean.setNewscontent(rs.getString(3)); bean.setNewscount(rs.getString(4)); bean.setNewsdate(rs.getString(5)); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return bean; } public int modify(String sql){ int result=0; Statement st=null; try { st=DataSource.getConnection().createStatement(); result=st.executeUpdate(sql); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { st.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return result; } public int updateNews(String newsid,String newsTitle,String newsContent){ return modify("update news set newstitle='"+newsTitle+"',newscontent='"+newsContent+"' where newsid="+newsid); } public int deleteId(String newsid){ return modify("delete from news where newsid="+newsid); } public NewsDataBean detail(String newsid){ NewsDataBean bean=new NewsDataBean(); Statement st=null; ResultSet rs=null; try { st=DataSource.getConnection().createStatement(); st.executeUpdate("update news set newscount=newscount+1 where newsid="+newsid); rs=st.executeQuery("select newsid,newstitle,newscontent,newscount,newsdate from news where newsid="+newsid); if(rs.next()){ bean.setNewsid(rs.getString(1)); bean.setNewstitle(rs.getString(2)); bean.setNewscontent(rs.getString(3)); bean.setNewscount(rs.getString(4)); bean.setNewsdate(rs.getString(5)); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return bean; } // public static void main(String[] args) { // // TODO Auto-generated method stub // // List list=new NewsLogicBean().findAll(); // System.out.println(list.size()); // } }